431. IJRM. Koen Pauwels on Word of Mouth.
Koen Pauwels
October 1, 2026
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Word of mouth has long been one of marketing’s most powerful tools, but marketers still struggle to understand what makes it effective. On this episode, we talk with Koen Pauwels, Professor of Marketing at Northeastern University and Editor-in-Chief of the International Journal of Research in Marketing (IJRM), about how word of mouth has changed from the early days of social media to the age of influencers and generative AI.
Pauwels’ research offers several important lessons for marketers:
Word of mouth can dramatically outperform paid marketing. His landmark 2009 research found that referrals had substantially greater long-term impact than promotional events or media appearances.
Not all word of mouth is equal. Brand-related conversations can be more valuable than conversations about advertising, while seemingly “neutral” mentions, such as someone simply saying they bought a product, can provide powerful social proof.
Influencer marketing depends on the objective. “Self-journalist” influencers may be better suited to building awareness, while specialized content creators can be more effective when consumers are closer to a purchase decision.
Online conversations are not necessarily representative. Social listening captures a particular sample of consumers, often overrepresenting extreme opinions and highly shareable brands or issues.
Real buzz travels. When a conversation moves beyond its original platform and gets picked up by other social networks, newsletters, podcasts or news media, it is more likely to represent meaningful cultural momentum.
Generative AI makes third-party credibility even more important. Clear brand messaging matters, but so does what independent people say about the brand. That external validation can influence how brands appear in AI-generated answers.
The takeaway for CMOs: word of mouth is too valuable to ignore, but too complicated to measure with a single social listening dashboard. Brands should cultivate genuine advocacy, understand what they are paying influencers to accomplish, and connect those investments to measurable business outcomes.
Click here for the IJRM Research Article
Click here for the 2009 paper
Click here for the 2026 update in JAMS
The Up Next podcast’s access to this content is courtesy of the International Journal of Research in Marketing, an international, double-blind peer -reviewed journal for marketing academics and practitioners. IJRM aims to contribute to the marketing discipline by providing high-quality, original research which advances marketing knowledge and techniques. As marketers increasingly draw on diverse and sophisticated methods, IJRM‘s target audience is comprised of marketing scholars, practitioners (e.g., marketing research and consulting professionals) and policymakers.
IJRM aims to be at the forefront of the marketing field with a particular emphasis on bringing timely ideas to market. The journal embraces innovative research with the potential to spur future research and influence practice. Hence, it welcomes contributions in various aspects of marketing. The editors, while accepting a wide array of scholarly contributions from different disciplinary approaches, especially encourage research that is novel, visionary or path breaking.
Interviewee
Koen Pauwels is the Associate Dean of Research and Distinguished Professor of Marketing at the D’Amore-McKim School of Business at Northeastern University. Formerly, he was Principal Research Scientist at Amazon Ads, with brand building and budget allocation recommendations reaching hundreds of thousands of advertisers. Koen received his Ph.D. from UCLA, where he was chosen Top 100 Inspirational Alumnus. After receiving tenure at the Tuck School of Business at Dartmouth, he helped build the startup Ozyegin University in Istanbul. Named a worldwide top 2% scientist, and ‘The Best Marketing Academic on the Planet’, Koen published over 100 articles on marketing effectiveness. Koen is the editor-in-chief of the International Journal of Research in Marketing and was the president of the American Marketing Association’s Academic Councile, and the Vice President for Practice at INFORMS. His books include Modeling Markets; and Advanced Methods for Modeling Markets; for analysts and Break the Wall: Why and How to Democratize Digital in Your Business, and It’s Not the Size of the Data – It’s How You Use It: Smarter Marketing with Analytics and Dashboards for managers. Koen frequently shares insights through his LinkedIn Newsletter Pauwels on Marketing and on retail media through his Substack Amazon Days.
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